README.md in google-cloud-env-1.2.1 vs README.md in google-cloud-env-1.3.0

@@ -5,14 +5,14 @@
 
 - [google-cloud-env API documentation](https://googleapis.dev/ruby/google-cloud-env/latest)
 
 ## Supported Ruby Versions
 
-This library is supported on Ruby 2.3+.
+This library is supported on Ruby 2.4+.
 
 Google provides official support for Ruby versions that are actively supported
 by Ruby Core—that is, Ruby versions that are either in normal maintenance or in
-security maintenance, and not end of life. Currently, this means Ruby 2.3 and
+security maintenance, and not end of life. Currently, this means Ruby 2.4 and
 later. Older versions of Ruby _may_ still work, but are unsupported and not
 recommended. See https://www.ruby-lang.org/en/downloads/branches/ for details
 about the Ruby support schedule.
 
 ## Versioning